考虑平面电磁波斜入射于三层介质的平行极化波传播问题.基于物理问题解决的认知模式及电磁场理论，导出了任意条件下的反射系数与透射系数，推广了电磁场与电磁波等教材中正入射情形下的反射与透射系数公式.讨论了几种特殊情形下的特殊结论，能够丰富教材内容，为未来更新电磁场与电磁波的教材做准备.这对于培养大学生的创新意识与研究能力具有积极意义，也为理工科的老师开展教学研究提供创新教学研究案例.

Consider the propagation of parallel polarized waves of plane electromagnetic waves obliquely incident on a three-layer medium. Based on the cognitive model of physics problem-solving and electromagnetic field theory, the reflection and transmission coefficients under arbitrary conditions are derived, and the formulas for reflection and transmission coefficients under normal incidence in textbooks such as electromagnetic fields and waves are extended. Several special conclusions are discussed in specific situations, which can enrich the content of the textbook and prepare for future updates on electromagnetic fields and waves. This has positive significance for cultivating college students' innovative consciousness and research ability, and also provides innovative teaching research cases for science and engineering teachers to conduct teaching research.